Poly (cyclic butylene terephthalate) / silicon dioxide nanocomposite

Abstract

The present invention relates to the technical field of polymer composites, in particular to a poly (cyclic butylene terephthalate)/silicon dioxide nanocomposite, wherein the added silicon dioxide is catalyst-modified nanosilicon dioxide.

What is claimed is: 
     
       1. A poly (cyclic butylene terephthalate)/silicon dioxide nanocomposite, characterized in that the added silicon dioxide is catalyst-modified nanosilicon dioxide having the following molecular structure: 
       
         
           
           
               
               
           
         
       
     
     
       2. The poly (cyclic butylene terephthalate)/silicon dioxide nanocomposite according to  claim 1 , characterized in that a method for preparing the catalyst-modified nanosilicon dioxide is specifically as follows:
 step (1): mixing nanosilicon dioxide with a cationic surfactant in an organic solvent to form a uniformly dispersed mixed solution; 
 step (2): adding an isocyanate silane coupling agent into the mixed solution obtained in step (1), and reacting to obtain isocyanate silane coupling agent-modified nanosilicon dioxide; and 
 step (3): reacting the isocyanate silane coupling agent-modified nanosilicon dioxide obtained in step (2) with a catalyst to obtain the catalyst-modified nanosilicon dioxide. 
 
     
     
       3. The poly (cyclic butylene terephthalate)/silicon dioxide nanocomposite according to  claim 2 , characterized in that the method for preparing the catalyst-modified nanosilicon dioxide is specifically as follows:
 step (1): dispersing 5 g to 12 g of tetraoctyl ammonium bromide into 1500 mL of dimethylbenzene, magnetically stirring for 20 min at an electromagnetic stirring speed of 500 r/min to obtain a solution A, adding 50 g of nanosilicon dioxide into the solution A, and ultrasonically treating for 1 h to obtain a uniformly dispersed mixed solution B; 
 step (2): transferring the mixed solution B into a reflux condenser, adding dropwise 15 mL of triethoxy isocyanate silane coupling agent under the protection of N 2 , reacting for 24 h in an oil bath at 80° C., separating the resulting product at the end of reaction, and washing with dimethylbenzene to obtain the silane coupling agent-modified nanosilicon dioxide; and 
 step (3): ultrasonically dispersing the modified nanosilicon dioxide into dimethylbenzene again, magnetically stirring under the protection of N 2 , adding 15 g of catalyst, reacting for 6 h at 80° C., separating the resulting product at the end of reaction, washing with THF to remove the non-grafted catalyst, finally washing the resulting product with ethyl alcohol and drying for 12 h at 60° C. in a vacuum oven to obtain the catalyst-modified nanosilicon dioxide. 
 
     
     
       4. The poly (cyclic butylene terephthalate)/silicon dioxide nanocomposite according to  claim 2 , characterized in that the catalyst is butylchlorodihydroxytin. 
     
     
       5. The poly (cyclic butylene terephthalate)/silicon dioxide nanocomposite according to  claim 2 , characterized in that a mixture of one or more of cerium acetate and cerium oxalate is added, with an addition amount of 3 to 5 parts by mass of the mixture with respect to 100 parts by mass of the silane coupling agent-modified nanosilicon dioxide, in the reaction of step (3). 
     
     
       6. The poly (cyclic butylene terephthalate)/silicon dioxide nanocomposite according to  claim 3 , characterized in that the catalyst is butylchlorodihydroxytin. 
     
     
       7. The poly (cyclic butylene terephthalate)/silicon dioxide nanocomposite according to  claim 3 , characterized in that a mixture of one or more of cerium acetate and cerium oxalate is added, with an addition amount of 3 to 5 parts by mass of the mixture with respect to 100 parts by mass of the silane coupling agent-modified nanosilicon dioxide, in the reaction of step (3).